1. Field of Invention
The present invention relates, in general, to a reference position setting method for an automated manual transmission and, more particularly, to a reference position setting method for controlling actuators in an automated manual transmission, in which shifting is performed by a selecting operation for selecting a shift rail to which a target shift range to be shifted is assigned and a shifting operation for moving the selected shift rail to shift into the target shift range, and the selecting operation and the shifting operation are realized using the actuators.
2. Description of Related Art
FIG. 1 illustrates a shift mechanism of a conventional automated manual transmission, particularly a double clutch transmission, to which the present invention can be applied.
In FIG. 1, two fingers F for a selecting operation caused by upward or downward movement and a shifting operation caused by pivoting are provided. Odd and even range selecting actuators 9 and 13 moving the two fingers in upward and downward directions, respectively, and odd and even range shifting actuators 11 and 15 pivoting the two fingers in leftward and rightward directions, respectively, are provided. As shown in FIG. 2, the two fingers F are configured so that, in respective shift gate patterns, they move up or down to perform the selecting operation, and move left or right to perform the shifting operation, thereby performing desired shifting.
Here, the odd and even range selecting actuators 9 and 13 are implemented as solenoid actuators, and the odd and even range shifting actuators 11 and 15 are configured as motors. In view of a characteristic of each motor, a separate position sensor is required to recognize a position of the finger F based on the operation of the motor. However, the position sensor increases the cost of a product, and is unfavorable in terms of configuration and weight of a package. Thus, a method of allowing a controller to accurately recognize the position of the finger F without the position sensor is required.
The following method has been used to recognize the position of the finger. In detail, the finger is forced to be located at a specific reference position when a vehicle is started. If the reference position is detected, the subsequent rotation of a motor is calculated on the basis of the reference position, and a position of the finger is followed up and recognized.
For reference, the reference positions of the two fingers F are shown in FIG. 2. Since the fingers F are not guaranteed to be located at the shown reference positions when a vehicle is started, an initialization operation of moving the fingers F to the reference positions should be performed.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.